Total joint arthroplasty is an operation involving the replacement of a damaged joint with an artificial joint in order to restore motion to the joint and function to the muscles and ligaments and other soft tissue structures that operate and control the joint.
The operation is typically performed on individuals with a painful, disabling arthritic joint that is no longer responsive to conservative treatment regimens. This operation typically entails implantation of two or more artificial joint members into respective natural joint members to replace deteriorated natural articulating surfaces with artificial equivalents.
Artificial joint assemblies have been devised for a variety of joints including hips, knees, ankles, shoulders, elbows, fingers, toes and wrists. While artificial joint components are designed to provide stable and permanent attachment to the natural adjacent body tissue(s), at attachment interfaces, over time, the artificial joint can relocate, loosen and/or wear, which can lead to a loss of function, bone deterioration and tissue debris generation. An increase in wear to the articulating surfaces of the artificial joint typically results in reduced function of the artificial joint and, in addition, produces joint debris, which are expelled from the joint area to the surrounding tissues and may cause adverse reactions in these tissues. As wear of a joint progresses and larger amount of particles are expelled to the surrounding tissues, further bone absorption and loosening of the joint implant may occur. Such loosening of a prosthetic joint implant and damage to surrounding tissues is often left undetected in a patient even if regularly checked by a physician.
Most modern methods currently employed for determining the extent of wear of an artificial joint rely on X-ray imaging, computer tomography, isotope bone scans, magnetic resonance and the like to image the implanted joint. Known methods are known to have insufficient accuracy or are technically difficult to perform and/or interpret, even by highly skilled professionals. Most modern joint replacement assemblies incorporate metal backed plastic components, metallic components, or ceramic components within metallic shells and the available imaging methods cannot produce sufficient resolution in order to determine artificial joint loosening and/or articulating surface wear.
As a result of inefficient detection methods, oftentimes the only indication of early joint loosening is the pain and discomfort suffered by the patient. Bone absorption may progress to a stage necessitating replacement surgery using larger implants, and/or bone grafts to accommodate for the lost bone tissue. The prognosis for success and service life of the implant after such a corrective operation is less predictable and depends, among other factors, on the extent of bone absorption suffered. If performed relatively early on, such corrective surgery has an increased chance of success. Therefore, a method capable of detecting the extent and depth of wear of the articulating surfaces of an artificial joint, or a method that is capable of detecting minute displacement of artificial joint components, is important both to the patient and the treating physician. Also, a more exact understanding of the condition of the components of numerous joints through their lives can facilitate faster improvements to joint design for better performance and longer life. Typical life of an artificial joint now is 15 to 20 years. With such high precision in vivo measurements, joint like may be able to be increased to 25 years and more in a matter of years of developments rather than over decades.
It will be appreciated that this background description has been created to aid the reader, and is not to be taken as an indication that any of the indicated problems were themselves appreciated in the art. While the described principles can, in some respects and embodiments, alleviate the problems inherent in other systems, it will be appreciated that the scope of the protected innovation is defined by the attached claims, and not by the ability of any disclosed feature to solve any specific problem noted herein.